1. Field of the Invention
The present invention relates to a steering apparatus for use in a vehicle, which apparatus employs a “steer-by-wire” system in which mechanical linkages between wheels and control components for controlling the wheels in a vehicle are replaced with electrical signals. The present invention is also relates to a mounting structure for mounting the apparatus on the vehicle.
2. Description of the Related Art
Conventional steering mechanisms developed and tested to date include those incorporating steer-by-wire technology, such as the mechanism described in non-patent Citation (Sumio Motoyama, “Steer-by-wire and Vehicle Motion Control” Jidosha Gijutsu Kai, February 2003, Vol. 57, pp. 39–43), for example. The greatest concern regarding such systems is how to ensure reliability in the event of system malfunction. A number of types have been proposed, such as one that switches over to conventional mechanical linkage in the event of a system malfunction, or one equipped with a backup actuator. In JP-A-2001-213342, JP-A-2003-137124 and JP-A-2003-165460, for example, these have been disclosed steering apparatus of various kinds employing steer-by-wire systems.
Each of these implementations of steer-by-wire technology has the advantage that by replacing steering control with electrical signals, it is relatively easy to make the devices compatible with ITS (Intelligent Traffic Systems), which dramatically expand controllability of maneuver stability control of vehicles. Additionally, eliminating mechanical linkages between steering control components and the wheels has the promise of reducing direct transmission of vibration from the wheels and engine.
However, the steering wheel or other control component that transmits the intention of the driver must be fastened to and supported by the vehicle body side, and thus in the same way as before, input load from power train components and the road surface as well as vibration amplified by various kinds of resonance systems belonging to the vehicle body side are transmitted from fastener portions to the control component, creating an unpleasant feeling for the driver.